From 4b16bfbf8f8013fefb49592d030ff87651ab48cb Mon Sep 17 00:00:00 2001 From: Zoltan Menyhart Date: Fri, 13 Jan 2006 17:25:23 +0100 Subject: [PATCH] [IA64] Fix bug in ia64 specific down() function Chen, Kenneth W wrote: > The memory order semantics for include/asm-ia64/semaphore.h:down() > doesn't look right. It is using atomic_dec_return, which eventually > translate into ia64_fetch_and_add() that uses release semantics. > Shouldn't it use acquire semantics? Use ia64_fetchadd() instead of atomic_dec_return() Acked-by: Ken Chen Signed-off-by: Tony Luck --- include/asm-ia64/semaphore.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/include/asm-ia64/semaphore.h b/include/asm-ia64/semaphore.h index bb8906285fab..f483eeb95dd1 100644 --- a/include/asm-ia64/semaphore.h +++ b/include/asm-ia64/semaphore.h @@ -61,7 +61,7 @@ static inline void down (struct semaphore *sem) { might_sleep(); - if (atomic_dec_return(&sem->count) < 0) + if (ia64_fetchadd(-1, &sem->count.counter, acq) < 1) __down(sem); } @@ -75,7 +75,7 @@ down_interruptible (struct semaphore * sem) int ret = 0; might_sleep(); - if (atomic_dec_return(&sem->count) < 0) + if (ia64_fetchadd(-1, &sem->count.counter, acq) < 1) ret = __down_interruptible(sem); return ret; } @@ -85,7 +85,7 @@ down_trylock (struct semaphore *sem) { int ret = 0; - if (atomic_dec_return(&sem->count) < 0) + if (ia64_fetchadd(-1, &sem->count.counter, acq) < 1) ret = __down_trylock(sem); return ret; } @@ -93,7 +93,7 @@ down_trylock (struct semaphore *sem) static inline void up (struct semaphore * sem) { - if (atomic_inc_return(&sem->count) <= 0) + if (ia64_fetchadd(1, &sem->count.counter, rel) <= -1) __up(sem); }